Using a rat model of experimental diabetes, the goal of this project is to work out a system of treating diabetes by transplantation of the pancreas from a fetal animal. The fetal pancreas is transplanted beneath the kidney capsule of diabetic rats. It has been found that optimal growth and function of the fetal organ results from a period of 3 weeks in a nomral animal prior to transfer to the diabetic rat. Alternatively prolonged insulin treatment of the diabetic rat after transplantation will enhance growth and function of the fetal pancreas. As determined by insulin content, the fetal pancreas of a rat attains 20-25% of the function of an adult organ. Future directions of this project are to determine the effect of anti-insulin antibodies and autoimmunity to islet tissue in the recipient on the function of a transplanted fetal pancreas. It is necessary in the diabetic rat, following transplantation, to determine the return to normal metabolism by measurement of enzyme activities in the liver. Techniques for preservation of the fetal rat pancreas by cryopreservation will be applied to the human fetal pancreas. Study of the developmental biology of the human fetal pancreas will be needed for consideration of the application of this method to humans.